1. Field
The present disclosure relates to casting of prefabricated concrete products in a casting production process. More precisely the present disclosure relates to an arrangement for curing concrete products and to a method for curing concrete products.
2. Description of Related Art
In casting production processes, the casting is performed in different stages at work stations, and different types of lines are used, for example circulating lines such as forced circulation lines and center conveyance lines. In forced circulation lines, mold tables and molds built on them are transferred by a roll trestle in a successive order from one work station, in which a process stage is performed, to a next work station, in which the next process stage is performed, and thus the process stage taking the longest time defines the speed of the forced circulation line. In circulating lines, mold tables, on which casting molds are built, are mounted on tracks and circulate through the work stations for the stages of the production process.
The casting lines thus comprise a plurality work stations between which the casting mold table is transferred for the different stages of the production process. The stages of the production process can comprise, for example, cleaning of the mold table, furnishing the mold table with fixed and detachable mold sidewalls to form the casting mold and setting of other required equipment, such as reinforcements etc., on the mold, casting of the concrete mass to the mold, together with required vibrating actions during the casting, leveling the upper surface of the product to be cast, curing the fresh cast product, demolding, in which the cast product is removed from the mold, generally together with tilting of the mold and removing the mold sidewalls from the mold table.
Depending on the type of the production process line, the line may comprise one or more work stations for one type of process stage.
The curing stage generally takes place at a curing chamber where temperature during the curing can be monitored and adjusted such that the surface of the concrete product to be cured remains moist in order to avoid cracks. taking into account that as temperature in the curing chamber increases, the moisture level decreases.
In the curing stage, the molds with cast products are generally located in columns of several molds on top of each other so that the area required by curing the products can be minimized. Further, the curing area is advantageously enclosed so that the heat released for the concrete during the curing process can be used for speeding up the curing process.
Typically, the curing chambers are continuously operating, such that at one end of the curing chamber fresh cast products to be cured are brought in, and at the other end, the cured cast products are taken out and transferred to the next process stage. Typically, the fresh cast product is brought to a free location of a column of the curing chamber, from which the cured cast product has been taken out so that in the curing chamber there are cast products of different curing stages, i.e. at different temperatures, at the same time. This is problematic in view of the known heating systems of the curing chambers as the relative moisture level is not optimal for cast products of different temperatures, and balance between temperature and moisture level is disturbed. A cold cast product that has just entered the curing chamber creates a high condensate level on its surface, but a warm cast product that has already been in the curing chamber for a longer time needs a higher relative moisture level for proper curing. In practice, the cold cast products define the relative moisture level of the curing chamber by condensing moisture from air.